C1 Atomic Structure Flashcards
What is an atom?
An atom is the smallest part of an element that can exist
What is an Element?
An element is a substance that contains only one type of atom
How are compounds formed?
Compounds are formed from elements by chemical reactions
What are sub-atomic particles? Give all three examples
Sub-atomic particles are the components that make up the atom. The protons and nuetrons inside the nucleus of the atom, the electrons orbiting around the nucleus.
Atoms are mostly ……
Empty space
Where is most of the mass thought to be concentrated in the atom?
In the nucleus, containing the protons and neutrons
What charge to protons have?
A positive charge
What is the relative charge of a proton?
+1
What charge do neutrons have?
They are neutral so therefore don’t have a charge
What is the realtive charge of a neutron?
0
What is the the charge of the nucleus?
Positive, as it contains protons.
What orbits the nucleus?
Electrons, in shells
How do electrons orbit the nucleus?
In energy levels (electron shells)
What charge do electrons have?
A negative charge
What is the relative charge of an electron?
-1
What is the atomic number?
It tells us the amount of protons in an element as is located below the symbol
How can we find the amount of electrons in an atom?
The atom will have the same amount of electrons as protons as it has an overall charge of zero
What is the atomic mass number?
This number is the sum of the amount of protons and neutrons in an atom. This is located above the symbol
How do we find the amount of neutrons in an atom?
Relative atomic mass - atomic mass = number of neutrons
What do scientists use to describe atoms?
Nuclear model
The nuclear model consists of ….
nucleus orbited by electrons
Every atom has what realtive charge?
Relative charge of zero
What is the radius of an atom?
0.1 nm (1x10^-10 m)
The radius of a nucleus is….
1x10^-14m
(less than 1/10,000 of that of the atom)
What is an isotope?
Isotops are atoms of the same element that have a different number of neutrons
How do you find the relative atomic mass of isotopes?
Isotope mass x Isotope abundance / 100
Isotopes have diiferent mass numbers because….
They have different number of neutrons
When was the first discovery of atoms?
Early greek philosopher Democritus, came up with the concept of atoms, however in the 1800’s John Dalton used experimental evidence to deduce that atoms were tiny spheres which couldn’t be divided.
What did JJ Thompson discover in 1897?
He discovered the electron and that atoms were made of smaller sub-atomic particles.
He also came up with the ‘Plum Pudding Model’
What was the Plum Pudding Model?
The Plum Pudding Model was a ball of positive charge with electrons embedded into it.
What was the Alpha Scattering Experiment and what did it lead to?
The Alpha Scattering Experiment was an experiment led by Ernest Rutherford in 1911 which fired alpha particles (large positively charged particles) at very thin gold foil. Some atoms went straight through, some had deflected off and some bounced straight back. This led to the ideal of the nuclear model.
What was the nuclear model?
- In 1913, Niels Bohr proposed that electrons orbit the nucleus in fixed shells in specific distances.
- This led to a diagram with protons in the centre with electrons surrounding it.
What is an ion?
An ion is a charged atom, which has either lost or gained electron/s to have a full outer shell
What is an electronic structure?
The order of how many electrons in each shell of an element
E.g.
Electronic structure of Potassium (K) is :
2,8,8,1
What order do the models of atom go in?
Simple atom —> Plum Pudding Model —> Nuclear Model —> Orbital Model —> Modern Atomic Model
What is biofuel?
Fuel made from animal or plant products.
What is chromatography?
When small amounts of dissolved substances are separated by running a solvent along a material (such as absorbent paper)
What did James Chadwick discover?
In 1932, James Chadwick provided evidence of a neutrons, leading to a nuclear model of nuetrons of protons in the neucleus with electrons orbiting it in specific distances.
Melting and boiling involve a transfer of energy….,
From the surroundings
Freezing and condensing involve a transfer of energy….
To the surroundings
What is the process of paper chromatography?
- Ink or plant dye is dotted along the pencil line
- As the paper is lowered into the solvent, some of the dye spreads up the paper
- The paper has absorbed the solvent, and the dye has spread further up the paper
What is the process of simple distiliation with salty water?
- Salty water is heated
- The water vapour cools in the condenser and drips into a beaker
- The water has condensed and is now in the beaker, the salt stays behind
What is a mixture made of?
Two or more substances that aren’t chemically combined together
